1. Field of the Invention
The present invention relates generally to a recording/reproducing device. More particularly, the present invention relates to a recording/reproducing device in the form of a disc drive device for rotationally driving a disc-shaped rotary recording medium (hereinafter referred to simply as a disc) to perform an information recording/reproducing operation using the disc.
2. Description of the Prior Art
To perform an information recording/reproducing operation using a flexible magnetic disc that is called a floppy disc (hereinafter referred to simply as an FD) serving as a rotational magnetic recording medium, a floppy disc drive device (hereinafter referred simply to as an FDD) has been hitherto used. As is well known, various kinds of office automation devices, apparatuses or the like have been remarkably developed in recent years. Similarly, FDDs each serving as an exterior memorizing device have accomplished remarkable development especially in respect of their design and construction in smaller dimensions accompanied by an enlarged capacity. In this connection, proposals have been made with respect to various kind of FDs for FDDs some of which are standardized at present. Among them, FD having a diameter of 8 inches, FD having a diameter of 5.25 inches and FD having a diameter of 3.5 inches have been widely put in practical use.
Recently, two FDDs each serving as an exterior memorizing device are often used for an office automation apparatus such as a word processor, a personal computer or the like. For example, with respect to a word processor, two FDDs are practically used in such a manner that one of them is employed for the purpose of reproducing a control program that is called a system soft for the word processor and then feeding a central processing unit of a main body of the word processor with the reproduced control program and other one is employed for the purpose of memorizing and storing data, e.g., documents created by operating the word processor.
However, when two same FDDs are arranged in parallel with each other, there arise drawbacks that a wide space is required for arrangement of them and a quantity of consumption of electricity is undesirably increased because a driving motor for driving an FD in each FDD consumes electricity.
To obviate the foregoing drawbacks, a proposal has been made as disclosed in Japanese Patent Application Laying-open No. 211376/1983. According to this prior invention, a so-called dual FDD is employed such that a single driving motor serving as a common driving power supply source to two FDDs is installed to rotationally drive two FDs.
However, since the conventional dual FDD is constructed such that the same kind of two FDDs are integrated with each other, an information recording/reproducing operation can be performed only for the same kind of FDs arranged in the both FDDs. For example, with respect to FD having a diameter of 5.25 inches (hereinafter referred to simply as a 5-inch FD), an information recording/reproducing operation can be performed only with 5-inch FDs. For this reason, there appear the following inconveniences under the current circumstance of various kinds of FDs widely used in many office automation apparatuses.
For example, when documents are created by using a 5-inch FD having a system soft widely employed for word processors and stored therein, they cannot be recorded and stored in a 3.5-inch FD. In addition, a system soft or data stored in the 5-inch FD cannot be transferred to the 3.5-inch FD and vice versa. In other words, a so-called dubbing operation cannot be performed between 5-inch FD and 3.5-inch FD. If there arises an unavoidable necessity for performing a dubbing operation, two FDDs, i.e., FDD for 3.5-inch FD and FDD for 5-inch FD should be prepared. This leads to the same drawbacks as mentioned above that a wide space is required for arrangement of two FDDs, and moreover, a large quantity of electricity is consumed.
To obviate these drawbacks, another proposal has been made as disclosed in Japanese Patent Application Laying-open No. 150271/1989. According to this prior invention, a single common driving power supply source to two FDs is arranged in FDD so as to make it possible to drive 3.5-inch FD and 5-inch FD only with a single driving motor. However, since the FDD is constructed such that a chucking mechanism for 3.5-inch FD and a chucking mechanism for 5-inch FD are arranged in a simply overlapped relationship, there remains still a problem in respect of design and construction of the FDD in smaller dimensions because of thickness of the FDD, although the FDD has an advantage that different kinds of recording media can be driven with a single driving power supply source.
Another drawback of the above proposal is that a recording medium having a smaller diameter should more deeply be inserted into the FDD, since different kinds of recording media, i.e., recording media each having a different diameter are rotationally driven about a common rotational center. To obviate this drawback, an insert slit on a front panel should be enlarged so as to enable a recording medium having a smaller diameter to be deeply inserted into the FDD with an operator's hand. Otherwise, a mechanism for automatically conveying a recording medium having a smaller diameter by utilizing rollers or the like should additionally be arranged in the FDD.